Phase 3 Trial of Crinecerfont in Adult Congenital Adrenal Hyperplasia.

BACKGROUND: Adrenal insufficiency in patients with classic 21-hydroxylase deficiency congenital adrenal hyperplasia (CAH) is treated with glucocorticoid replacement therapy. Control of adrenal-derived androgen excess usually requires supraphysiologic glucocorticoid dosing, which predisposes patients to glucocorticoid-related complications. Crinecerfont, an oral corticotropin-releasing factor type 1 receptor antagonist, lowered androstenedione levels in phase 2 trials involving patients with CAH. METHODS: In this phase 3 trial, we randomly assigned adults with CAH in a 2:1 ratio to receive crinecerfont or placebo for 24 weeks. Glucocorticoid treatment was maintained at a stable level for 4 weeks to evaluate androstenedione values, followed by glucocorticoid dose reduction and optimization over 20 weeks to achieve the lowest glucocorticoid dose that maintained androstenedione control (≤120% of the baseline value or within the reference range). The primary efficacy end point was the percent change in the daily glucocorticoid dose from baseline to week 24 with maintenance of androstenedione control. RESULTS: All 182 patients who underwent randomization (122 to the crinecerfont group and 60 to the placebo group) were included in the 24-week analysis, with imputation of missing values; 176 patients (97%) remained in the trial at week 24. The mean glucocorticoid dose at baseline was 17.6 mg per square meter of body-surface area per day of hydrocortisone equivalents; the mean androstenedione level was elevated at 620 ng per deciliter. At week 24, the change in the glucocorticoid dose (with androstenedione control) was -27.3% in the crinecerfont group and -10.3% in the placebo group (least-squares mean difference, -17.0 percentage points; P<0.001). A physiologic glucocorticoid dose (with androstenedione control) was reported in 63% of the patients in the crinecerfont group and in 18% in the placebo group (P<0.001). At week 4, androstenedione levels decreased with crinecerfont (-299 ng per deciliter) but increased with placebo (45.5 ng per deciliter) (least-squares mean difference, -345 ng per deciliter; P<0.001). Fatigue and headache were the most common adverse events in the two trial groups. CONCLUSIONS: Among patients with CAH, the use of crinecerfont resulted in a greater decrease from baseline in the mean daily glucocorticoid dose, including a reduction to the physiologic range, than placebo following evaluation of adrenal androgen levels. (Funded by Neurocrine Biosciences; CAHtalyst ClinicalTrials.gov number, NCT04490915.).

Evidence of the Role of Inflammation and the Hormonal Environment in the Pathogenesis of Adrenal Myelolipomas in Congenital Adrenal Hyperplasia.

Adrenal myelolipomas (AML) are composed of mature adipose and hematopoietic components. They represent approximately 3 percent of adrenal tumors and are commonly found in patients with congenital adrenal hyperplasia (CAH). CAH provides a unique environment to explore AML pathogenesis. We aimed to evaluate the role of the immune system and hormones that accumulate in poorly controlled CAH in the development of AML. When compared to normal adrenal tissue, CAH-affected adrenal tissue and myelolipomas showed an increased expression of inflammatory cells (CD68, IL2Rbeta), stem cells (CD117) B cells (IRF4), and adipogenic markers (aP2/FABP4, AdipoQ, PPARγ, Leptin, CideA), and immunostaining showed nodular lymphocytic accumulation. Immunohistochemistry staining revealed a higher density of inflammatory cells (CD20, CD3, CD68) in CAH compared to non-CAH myelolipomas. In vitro RNA-sequencing studies using NCI-H295R adrenocortical cells with exogenous exposure to ACTH, testosterone, and 17-hydroxyprogesterone hormones, showed the differential expression of genes involved in cell cycle progression, phosphorylation, and tumorigenesis. Migration of B-lymphocytes was initiated after the hormonal treatment of adrenocortical cells using the Boyden chamber chemotaxis assay, indicating a possible hormonal influence on triggering inflammation and the development of myelolipomas. These findings demonstrate the important role of inflammation and the hormonal milieu in the development of AML in CAH.

The management of congenital adrenal hyperplasia during preconception, pregnancy, and postpartum.

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders of steroidogenesis of the adrenal cortex, most commonly due to 21-hydroxylase deficiency caused by mutations in the CYP21A2 gene. Although women with CAH have decreased fecundity, they are able to conceive; thus, if pregnancy is not desired, contraception options should be offered. If fertility is desired, women with classic CAH should first optimize glucocorticoid treatment, followed by ovulation induction medications and gonadotropins if needed. Due to the possible pregnancy complications and implications on the offspring, preconception genetic testing and counseling with a high-risk obstetrics specialist is recommended. For couples trying to avoid having a child with CAH, care with a reproductive endocrinology and infertility specialist to utilize in vitro fertilization can be offered, with or without preimplantation genetic testing for monogenic disorders. Prenatal screening and diagnosis options during pregnancy include maternal serum cell free-DNA for sex of the baby, and chorionic villus sampling and amniocentesis for diagnosis of CAH. Pregnant women with classic CAH need glucocorticoids to be adjusted during the pregnancy, at the time of delivery, and postpartum, and should be monitored for adrenal crisis. Maternal and fetal risks may include chorioamnionitis, maternal hypertension, gestational diabetes, cesarean section, and small for gestational age infants. This review on CAH due to 21-hydroxylase deficiency highlights reproductive health including genetic transmission, contraception options, glucocorticoid management, fertility treatments, as well as testing, antenatal monitoring, and management during pregnancy, delivery, and postpartum.

Adrenal morphology and associated comorbidities in congenital adrenal hyperplasia.

OBJECTIVE: Adrenonodular hyperplasia and tumour formation are potential long-term complications of congenital adrenal hyperplasia (CAH) with little known regarding the clinical implications. Our aim was to describe volumetric adrenal morphology and determine the association between radiological findings and comorbidities in adults with classic CAH. DESIGN: This was a cross-sectional study of 88 patients (mean age 29.2 ± 13 years, 47 females) with classic CAH seen in a tertiary referral centre. METHODS: CT imaging, performed at study entry or when reaching adulthood, was used to create 3-dimensional volumetric models. Clinical, genetic and hormonal evaluations were collected and correlated with adrenal morphology and tumour formation. RESULTS: Over one-third of the cohort was obese. 53% had elevated 17-OH-progesterone or androstenedione; and 60% had adrenal hyperplasia. Tumours included 11 myelolipomas, 8 benign adrenocortical adenomas, 1 pheochromocytoma and 50% of men had testicular adrenal rest tissue. CAH patients with adrenal hyperplasia had significantly higher number of comorbidities than those with morphologically normal adrenals (P = 0.03). Variables that positively correlated with adrenal volume included hypogonadal/oligomenorrhoeic status, hypertension, androstenedione, aldosterone, and triglyceride levels, and in women, low HDL and insulin resistance. Elevated aldosterone was observed in a subset of patients with simple virilizing CAH. CONCLUSIONS: Adrenocortical hyperplasia is associated with a number of comorbidities, especially hypogonadism. Aldosterone production associated with adrenal enlargement may play a role in the development of metabolic risk factors. Further studies are needed to assess the long-term impact of the excess adrenal steroid milieu associated with adrenal enlargement to develop improved management strategies for CAH.

Complement component 4 variations may influence psychopathology risk in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

CYP21A2 defects result in congenital adrenal hyperplasia (CAH), an autosomal recessive disorder characterized by impaired adrenal steroidogenesis. CYP21A2 lies within the major histocompatibility complex in an area of the genome highly susceptible to genetic variation. Alterations in the neighboring complement component 4 isotypes C4A and C4B have been associated with psychiatric and autoimmune disease. The purpose of this study was to evaluate C4A and C4B in patients with CAH in relation to CYP21A2 genotype and psychiatric and autoimmune comorbidity. We determined the copy numbers of C4A and C4B in 145 patients with CAH (median age: 15.5 years, IQR: 16.8) and 108 carrier relatives (median age: 41.5 years, IQR: 12.0) and evaluated serum C4 concentrations. Comorbidity was determined by medical record review. Only 30% of subjects had the expected two copies each of the two C4 genes. C4B copy number determined total C4 copy number and serum C4 concentration, negatively correlated with carriership of a 30-kb deletion (P < 10- 5), and positively correlated with carriership of p.V281L (P < 10- 5). High C4A copy number (≥ 3) was associated with increased risk of having an externalizing psychiatric condition (relative risk: 2.67, 95% CI: 1.03-6.89, P = 0.04). No association was found between C4 copy number and autoimmune disease. Mutation-specific C4 structural variations commonly occur in patients with CAH and may have important clinical consequences, including increased risk of psychiatric morbidity. Trial registration NCT00250159 (November 7, 2005).

Congenital adrenal hyperplasia.

Congenital adrenal hyperplasia is a group of autosomal recessive disorders encompassing enzyme deficiencies in the adrenal steroidogenesis pathway that lead to impaired cortisol biosynthesis. Depending on the type and severity of steroid block, patients can have various alterations in glucocorticoid, mineralocorticoid, and sex steroid production that require hormone replacement therapy. Presentations vary from neonatal salt wasting and atypical genitalia, to adult presentation of hirsutism and irregular menses. Screening of neonates with elevated 17-hydroxyprogesterone concentrations for classic (severe) 21-hydroxylase deficiency, the most common type of congenital adrenal hyperplasia, is in place in many countries, however cosyntropin stimulation testing might be needed to confirm the diagnosis or establish non-classic (milder) subtypes. Challenges in the treatment of congenital adrenal hyperplasia include avoidance of glucocorticoid overtreatment and control of sex hormone imbalances. Long-term complications include abnormal growth and development, adverse effects on bone and the cardiovascular system, and infertility. Novel treatments aim to reduce glucocorticoid exposure, improve excess hormone control, and mimic physiological hormone patterns.

Long-term use of continuous subcutaneous hydrocortisone infusion therapy in patients with congenital adrenal hyperplasia.

BACKGROUND: In a phase 2 short-term (6 months) study of patients with congenital adrenal hyperplasia (CAH), continuous subcutaneous hydrocortisone infusion (CSHI) was found to be a safe, effective and well-tolerated method of replacing cortisol with improved disease and patient-related outcomes. OBJECTIVE: To evaluate the safety and efficacy of long-term CSHI. DESIGN: Single-centre, open-label, phase 2 extension study. PATIENTS: Five adults with classic CAH. MEASUREMENTS: Biomarkers of disease control, metabolic indices and health-related quality-of-life (HRQoL) estimates. RESULTS: Six of eight patients chose to continue on long-term CSHI therapy. Compared to baseline, eighteen months of CSHI resulted in decreased (P = 0.043) 0700-hour ACTH, 17-hydroxyprogesterone, androstenedione and progesterone; increased whole-body lean mass (P = 0.024); and improved HRQoL, especially symptoms of adrenal insufficiency (P = 0.003). Findings at six and eighteen months did not differ, and improvements achieved in androgen control, lean body mass and HRQoL after 6 months of CSHI were maintained at eighteen months. The hydrocortisone dose appeared to decrease with time [6 vs 18 months: 38.3 ± 8.8 vs 33.6 ± 12.2 mg/day (P = 0.062)], especially in women receiving oral contraceptives. Reduction of testicular adrenal rest and adrenal size observed at 6 months remained stable. In one patient, an adrenal adenoma continually decreased over time. Subjective improvement in hirsutism was reported. CONCLUSIONS: Long-term use of CSHI is a safe and well-tolerated treatment option in a select set of adults with classic CAH. Improvements observed short term in disease control and subjective health status continued long term.

Revisiting the prevalence of nonclassic congenital adrenal hyperplasia in US Ashkenazi Jews and Caucasians.

PurposeNonclassic 21-hydroxylase deficiency, a mild form of congenital adrenal hyperplasia (CAH), is estimated to be the most common autosomal recessive condition, with an especially high prevalence in Ashkenazi Jews (3.7% affected, 30.9% carriers), based on a 1985 HLA-B linkage study of affected families. Affected individuals, especially women, may suffer from hyperandrogenism and infertility. State-of-the-art genetic studies have not been done to confirm these remarkable rates.MethodsCYP21A2 genotyping was performed in 200 unrelated healthy Ashkenazi Jewish subjects and 200 random US Caucasians who did not self-identify as a specific ethnicity using multiplex minisequencing, real-time polymerase chain reaction and junction site analysis.ResultsNonclassic CAH carriership was found similarly in 15% (95% confidence interval (CI): 10.4-20.7) of Ashkenazi Jews and 9.5% (95% CI: 5.8-14.4) of Caucasians (P=0.13). The proportion of Ashkenazi Jewish nonclassic CAH carriers (0.15 versus 0.309, P<0.0001) and disease affected (0.005 versus 0.037, P=0.009) was not as high as previously reported. The estimated prevalence of nonclassic CAH in Caucasians was 1 in 200 (0.5%, 95% CI: 0.01-2.8).ConclusionNonclassic CAH is a common condition, regardless of ethnicity, and should be considered with preconception and infertility counseling.

Androgens correlate with increased erythropoiesis in women with congenital adrenal hyperplasia.

OBJECTIVE: Hyperandrogenism in congenital adrenal hyperplasia (CAH) provides an in vivo model for exploring the effect of androgens on erythropoiesis in women. We investigated the association of androgens with haemoglobin (Hb) and haematocrit (Hct) in women with CAH. DESIGN: Cross-validation study. PATIENTS: Women with CAH from Sheffield Teaching Hospitals, UK (cohort 1, the training set: n = 23) and National Institutes of Health, USA (cohort 2, the validation set: n = 53). MEASUREMENTS: Androgens, full blood count and basic biochemistry, all measured on the same day. Demographic and anthropometric data. RESULTS: Significant age-adjusted correlations (P < 0·001) were observed for Ln testosterone with Hb and Hct in cohorts 1 and 2 (Hb r = 0·712 & 0·524 and Hct r = 0·705 & 0·466), which remained significant after adjustments for CAH status, glucocorticoid treatment dose and serum creatinine. In the combined cohorts, Hb correlated with androstenedione (P = 0·002) and 17-hydroxyprogesterone (P = 0·008). Hb and Hct were significantly higher in cohort 1 than those in cohort 2, while there were no group differences in androgen levels, glucocorticoid treatment dose or body mass index. In both cohorts, women with Hb and Hct in the highest tertile had significantly higher testosterone levels than women with Hb and Hct in the lowest tertile. CONCLUSIONS: In women with CAH, erythropoiesis may be driven by androgens and could be considered a biomarker for disease control.

Ehlers-Danlos Syndrome Caused by Biallelic TNXB Variants in Patients with Congenital Adrenal Hyperplasia.

Some variants that cause autosomal-recessive congenital adrenal hyperplasia (CAH) also cause hypermobility type Ehlers-Danlos syndrome (EDS) due to the monoallelic presence of a chimera disrupting two flanking genes: CYP21A2, encoding 21-hydroxylase, necessary for cortisol and aldosterone biosynthesis, and TNXB, encoding tenascin-X, an extracellular matrix protein. Two types of CAH tenascin-X (CAH-X) chimeras have been described with a total deletion of CYP21A2 and characteristic TNXB variants. CAH-X CH-1 has a TNXB exon 35 120-bp deletion resulting in haploinsufficiency, and CAH-X CH-2 has a TNXB exon 40 c.12174C>G (p.Cys4058Trp) variant resulting in a dominant-negative effect. We present here three patients with biallelic CAH-X and identify a novel dominant-negative chimera termed CAH-X CH-3. Compared with monoallelic CAH-X, biallelic CAH-X results in a more severe phenotype with skin features characteristic of classical EDS. We present evidence for disrupted tenascin-X function and computational data linking the type of TNXB variant to disease severity.

Cortical bone mineral density in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

BACKGROUND: Prior studies reveal that bone mineral density (BMD) in congenital adrenal hyperplasia (CAH) is mostly in the osteopaenic range and is associated with lifetime glucocorticoid dose. The forearm, a measure of cortical bone density, has not been evaluated. OBJECTIVE: We aimed to evaluate BMD at various sites, including the forearm, and the factors associated with low BMD in CAH patients. METHODS: Eighty CAH adults (47 classic, 33 nonclassic) underwent dual-energy-x-ray absorptiometry and laboratory and clinical evaluation. BMD Z-scores at the AP spine, total hip, femoral neck, forearm and whole body were examined in relation to phenotype, body mass index, current glucocorticoid dose, average 5-year glucocorticoid dose, vitamin D, 17-hydroxyprogesterone, androstenedione, testosterone, dehydroepiandrosterone and dehydroepiandrosterone sulphate (DHEAS). RESULTS: Reduced BMD (T-score <-1 at hip, spine, or forearm) was present in 52% and was more common in classic than nonclassic patients (P = 0·005), with the greatest difference observed at the forearm (P = 0·01). Patients with classic compared to nonclassic CAH, had higher 17-hydroxyprogesterone (P = 0·005), lower DHEAS (P = 0·0002) and higher non-traumatic fracture rate (P = 0·0005). In a multivariate analysis after adjusting for age, gender, height standard deviation, phenotype and cumulative glucocorticoid exposure, higher DHEAS was independently associated with higher BMD at the spine, radius and whole body. CONCLUSION: Classic CAH patients have lower BMD than nonclassic patients, with the most affected area being the forearm. This first study of forearm BMD in CAH patients suggests that low DHEAS may be associated with weak cortical bone independent of glucocorticoid exposure.

Gonadotropin-Releasing Hormone Agonist Therapy and Longitudinal Bone Mineral Density in Congenital Adrenal Hyperplasia.

CONTEXT: Children with congenital adrenal hyperplasia (CAH) are at risk for early puberty. Gonadotropin-releasing hormone analog (GnRHa) is frequently used and can decrease bone mineral density (BMD). OBJECTIVE: Our aim was to investigate the effect of GnRHa therapy on BMD in a longitudinal study of patients with CAH spanning both childhood and adulthood. DESIGN AND SETTING: Sixty-one patients with classic CAH due to 21-hydroxylase deficiency (20 treated with GnRHa) were followed with dual-energy X-ray absorptiometry (DXA) scans at puberty onset, attainment of adult height, and during early adulthood. MAIN OUTCOME MEASURES: Whole body, lumbar spine, femoral neck, total hip, and distal radius BMD z-score at adult height. Longitudinal BMD and adult height were also assessed. RESULTS: Twenty patients received GnRHa for an average of 4.5 ± 2 years. There were no differences in BMD between GnRHa-treated and -untreated groups at adult height for all sites. Overall, the follow-up DXA during early adulthood showed decreases in BMD z-scores for whole body (P = .01), lumbar spine (P < .0001), femoral neck (P = .06), total hip (P = .009), and distal radius (P = .05). GnRHa treatment correlated with improved height outcomes compared to predicted height at puberty onset after adjusting for midparental height (P = .02). Patients in both groups achieved similar adult height. CONCLUSION: In children with CAH, GnRHa does not compromise BMD. However, BMD decreases with time and during the second and third decades of life is a possible effect of chronic supraphysiologic glucocorticoids. Children with CAH who experience early puberty benefit from GnRHa treatment as evidenced by the positive effect on height.

Sexual dimorphism in anxiety is programmed in-utero by sex-steroids: Proof of concept using a disease-model and stress responses to COVID pandemic.

Sex differences in the psychological impact of the COVID-19 pandemic have been consistently reported, showing disproportionally high rates of anxiety/distress in women relative to men. The mechanisms underlying this sexual dimorphism remain unclear. The present study queries the potential protective role of early hyperandrogenism on brain development. A natural model of sex-steroids abnormality, classic congenital adrenal hyperplasia (CAH), was used to test this question. CAH is characterized by adrenal androgen overproduction in utero (prenatal) through the neonatal critical developmental period. An online survey collected information on subjective responses to the COVID-19 pandemic. Matched on demographic variables, 60 adults carrying a diagnosis of classic CAH and 240 adults from the general population (non-CAH) were compared on levels of anxiety/distress in the first year of the COVID-19 pandemic (May 2020-April 2021). Structural Equation Modeling was used to test the modulation by CAH status of Sex effects on anxiety/distress. Results revealed lower levels of anxiety/distress in the female CAH group compared to the other 3 groups (male CAH, female non-CAH, and male non-CAH). This finding suggests that pre-neonatal hyperandrogenism might impact the development of neural circuits underlying anxiety processes, in a way that enhances resilience to chronic stress.

Course of COVID-19 infection in patients with congenital adrenal hyperplasia.

Context: Patients with primary adrenal insufficiency due to congenital adrenal hyperplasia (CAH) are at risk for adrenal crisis during infectious illnesses. Increased risk of infection including COVID-19 has been variably reported. Objective: To evaluate COVID-19 illness outcomes and stress dose practices in a large cohort of patients with CAH during the first two years of the pandemic and compare observations of COVID-19 infection in patients with CAH to the general USA population. Methods: Between March 2020 and November 2022, patients with CAH followed at the National Institutes of Health Clinical Center were queried about COVID-19 infection during their routine visits. Cases of COVID-19 were compared to controls. COVID-19 infection rates and symptoms were compared to general USA population data from the Centers for Disease Control and Prevention. Results: Of 168 patient visits, there were 54 (32%) cases of COVID-19 infection, and 15 (28%) were pediatric. Overall an association was found between acquiring COVID-19 and obesity (p=0.018), and adults acquiring COVID-19 were on lower doses of fludrocortisone (p=0.008). Fewer cases of COVID-19 infection were reported in those receiving hydrocortisone or modified-release hydrocortisone compared to longer acting glucocorticoids (p=0.0018). In our CAH population, the pattern of COVID-19 infection rates and COVID-related symptomatology were similar to those observed in the general USA population. Most patients with the presumed alpha variant reported anosmia and ageusia, while gastrointestinal symptoms were commonly reported during the delta and omicron waves. Stress dosing occurred in 30/54 cases, and 7 received parenteral hydrocortisone. Two hospitalizations occurred; one pediatric and one adult, both with co-morbidities. There were 5 emergency room visits and no reported deaths. Conclusion: Patients with CAH with close follow-up do not appear to be at increased risk of acquiring COVID-19 or to have a more severe course of COVID-19 compared to the general USA population. Obesity may increase risk of acquiring COVID-19 in patients with CAH, and overall infection risk may be lower in those receiving short-acting and circadian glucocorticoid replacement therapy. Established age-appropriate guidelines for stress dosing during infectious illnesses should be used for patients with CAH and COVID-19. COVID-19 specific guidelines are not indicated. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT00250159.

CAHQL: A patient reported outcome instrument to assess health-related quality of life in congenital adrenal hyperplasia.

CONTEXT: Measuring health-related quality of life (HRQoL) is a crucial aspect of evaluating health care outcomes. Patients with congenital adrenal hyperplasia (CAH) often self-report deficiencies in HRQoL. OBJECTIVE: The aim of our study was to develop a disease-specific patient reported outcome (PRO) instrument to evaluate the HRQoL of patients >16 years old with classic congenital adrenal hyperplasia (CAH). DESIGN, SETTING AND OUTCOMES: Following the FDA guidelines for developing PRO instruments, we developed a conceptual framework for the instrument. A preliminary instrument was created after interviewing a representative sample of 12 patients with CAH between 16 to 68 years old and 3 parents, and obtaining expert feedback from 4 endocrinologists. The instrument was edited after cognitive interviews with 6 patients. Internal consistency of the instrument was evaluated using Cronbach's alpha. Validity was assessed by comparing the scores of our instrument with scores from widely used validated instruments for HRQoL and PRO not specific to CAH. RESULTS: Sixty-nine patients 16 to 75 years old participated in validating our preliminary instrument. The final questionnaire consists of 44 questions within 7 domains: General Health, Adrenal Insufficiency, Glucocorticoid Excess, Physical Functioning, Mental Health and Cognition, Social Functioning, and Sexual Functioning, with acceptable internal consistency (Chronbach's alpha≥0.6) and validity (r = -0.350 to 0.866). CONCLUSION: CAHQL is the first validated PRO instrument to capture disease specific HRQoL outcomes in CAH. In addition to its anticipated use in the clinical setting, the instrument could be used to assess the efficacy of novel treatments in development.

Comparison of modified-release hydrocortisone capsules versus prednisolone in the treatment of congenital adrenal hyperplasia.

BACKGROUND: Prednisolone and prednisone are recommended treatment options for adults with Congenital Adrenal Hyperplasia (CAH); however, there is no randomised comparison of prednis(ol)one with hydrocortisone. OBJECTIVE: To assess 17-hydroxyprogesterone (17OHP) levels and glucocorticoid dose in CAH comparing prednis(ol)one versus modified-release hydrocortisone (MRHC). DESIGN: Six-month open-label randomised phase 3 study and interim analysis of a single-arm extension study. METHODS: Hydrocortisone dose equivalent and 09:00h 17OHP from 48 patients taking prednis(ol)one at baseline. RESULTS: At baseline, the median hydrocortisone dose equivalent was 30 mg /day and 17OHP was <36nmol/l (3X upper limit of normal) in 56% of patients. Patients were randomised to continue prednis(ol)one or switch to MRHC at the same hydrocortisone equivalent dose. At 4 weeks, 94% on MRHC and 71% on prednis(ol)one had 17OHP <36nmol/l. At 18 months in the extension study of MRHC, the median MRHC dose was 20 mg /day and 82% had 17OHP <36nmol/l. The percent of patients with 17OHP <36nmol/l on a hydrocortisone dose equivalent ≤25mg /day was greater at 18 months in the extension study on MRHC than while on prednis(ol)one at baseline: 57% vs 27%, P=0.04. In the randomised study, no patients had an adrenal crisis on MRHC and one on prednisolone. In the extension study (221 patient years), there were 12 adrenal crises in 5 patients (5.4/100 patient years). CONCLUSIONS: MRHC reduces 17OHP at 09:00h compared to prednis(ol)one and the dose of MRHC can be down-titrated over time in the majority of patients.

Pseudogene TNXA Variants May Interfere with the Genetic Testing of CAH-X.

CAH-X is a hypermobility-type Ehlers-Danlos syndrome connective tissue dysplasia affecting approximately 15% of patients with 21-hydroxylase deficiency (21-OHD) congenital adrenal hyperplasia (CAH) due to contiguous deletion of CYP21A2 and TNXB genes. The two most common genetic causes of CAH-X are CYP21A1P-TNXA/TNXB chimeras with pseudogene TNXA substitution for TNXB exons 35-44 (CAH-X CH-1) and TNXB exons 40-44 (CAH-X CH-2). A total of 45 subjects (40 families) from a cohort of 278 subjects (135 families of 21-OHD and 11 families of other conditions) were found to have excessive TNXB exon 40 copy number as measured by digital PCR. Here, we report that 42 subjects (37 families) had at least one copy of a TNXA variant allele carrying a TNXB exon 40 sequence, whose overall allele frequency was 10.3% (48/467). Most of the TNXA variant alleles were in cis with either a normal (22/48) or an In2G (12/48) CYP21A2 allele. There is potential interference with CAH-X molecular genetic testing based on copy number assessment, such as with digital PCR and multiplex ligation-dependent probe amplification, since this TNXA variant allele might mask a real copy number loss in TNXB exon 40. This interference most likely happens amongst genotypes of CAH-X CH-2 with an in trans normal or In2G CYP21A2 allele.